a. Field of the Invention
This invention relates to a method of the oxidation of alicyclic hydrocarbons having therein substituent groups by the use of liquid nitrogen dioxide (N.sub.2 O.sub.4).
b. Description of Prior Arts
Oxidizing agents to be used for the oxidation reaction of organic substances are those selected from inorganic peroxides, organic peroxides, nitric acid, oxygen, or gases containing therein molecular oxygen (e.g., air), and so forth. For the purpose of this reaction, a catalyst is used in the main.
There have been known various methods for producing adipic acid in accordance with conventional techniques. For its production in an industrial scale, there have been adopted two major methods of: (1) hydrogenating acrylonitrile in an electro-chemical manner, followed by dimerizing the same to produce dinitrile, and then hydrolyzing dinitrile to obtain adipic acid; and (2) hydrogenating and dimerizing acrylic acid in dimethyl sulfoxide as the solvent by using sodium amalgam to obtain adipic acid. However, methods which are still predominant as the major production system in a large industrial scale are those which utilize cyclohexane as the starting material to be oxidized into adipic acid. Representative of such methods are as follows.
(a) "Chemical Technology", 1974 (9), pp. 555-559 discloses a method for producing adipic acid by oxidizing cyclohexane with molecular oxygen under pressure by the use of a solvent, a reaction initiator, and a catalyst.
(b) "Encyklopaedie der technischen Chemie" by Ulmann, 1953, Vol. 3, page 95 describes a method for producing adipic acid by oxidizing cyclohexane with nitric acid under pressure.
(c) "Encyklopaedic der technischen Chemie" by Ulmann, 1973, Vol. 7, page 108 describes a method for producing adipic acid indirectly from cyclohexane, wherein the acid is obtained by first oxidizing cyclohexane with molecular oxygen under pressure in the presence of a catalyst to thereby produce a mixture of cyclohexanol and cyclohexanone, and immediately oxidizing this mixture with molecular oxygen under pressure, or oxidizing each of the abovementioned components, after it is separated from the mixture, with molecular oxygen under normal pressure in the presence of a catalyst, whereby obtaining adipic acid. As another method, cyclohexanone is oxidized with nitric acid in the presence of a catalyst.
Besides the abovementioned methods of producing adipic acid in an industrial scale, the below-listed methods are known.
(d) Japanese Patent Publication No. 39-3812; "Industrial and Engineering Chemistry Design and Development", Vol. 4, No. 4, 1965, pp. 411-420; and "Industrial and Engineering Chemistry", Vol. 47, No. 4, 1955, pp. 782-785 describe method of producing adipic acid by the radical reaction, wherein cyclohexane is oxidized with nitrogen dioxide (NO.sub.2) in the presence, or absence, of a catalyst.
(e) Japanese Patent Publication No. 44-24094; and Japanese Patent Application No. 51-39270 (filed April 9, 1976) disclose reactions to produce adipic acid, wherein cyclohexane is oxidized with nitrogen dioxide (NO.sub.2) under irradiation of ultra-violet rays. The abovementioned Japanese Patent Application No. 51-39270 was filed by the applicants of the present application, the content of which is a photo-chemical reaction between nitrogen dioxide and cyclohexane with particular importance being attached to the presence of oxygen.
Next, the known methods for producing 1,10-decanedicarboxylic acid are as follows.
(f) "Chemical Abstract", Vol. 84, No. 9, 1976, 58652g discloses that 1,10-decanedicarboxylic acid is produced at a rate of yield of 88% by oxidizing cyclododecanol, or cyclododecanone, or a mixture of both, with nitric acid using vanadium and its compounds, or antimony and its compounds as the catalyst, to thereby open the ring.
(g) "Chemical Abstract", Vol. 84, No. 11, 1976, 73659r discloses the 1,10-decanedicarboxylic acid is produced, at a rate of selection of 94 to 96% and at a rate of conversion of 20 to 30%, by oxidizing cyclododecane with ozone-containing oxygen or air in nitro-methane as the solvent, and in the presence of manganese acetate as the catalyst, to thereby open the ring.
(h) Japanese Patent Application No. 43-40195 (filed June 13, 1965) describes that adipic acid is produced from cyclohexene, and that suberic acid is produced from cyclooctane, according to which cyclo-alkene having the carbon atoms of from 5 to 12 (C.sub.5 -C.sub.12) is oxidized with oxygen or gases containing therein molecular oxygen under pressure, using a lower carboxylic acid as the solvent and a salt of mercury or nickel, chromium, zinc (Ni.Cr.Zn) as the catalyst to open the ring, thereby obtaining dibasic fatty acids corresponding to the respective carbon atoms.